This section illustrates useful background information without admission of any technique described herein being representative of the state of the art.
Hyperspectral, or multispectral imaging, is increasingly used in numerous applications and accordingly, cost effective and simple arrangements are needed.
Previously hyperspectral imaging has been performed for example by using pixelized multispectral filters, by using a filter wheel and by using multiplexed LED illumination. Such arrangements often require complex manufacturing processes and are not easily adaptable to different spectral wavelength ranges. In these arrangements it is not possible to adjust wavelength continuously because the pixelized multispectral filters are permanently on top of pixels and the filter wheel can only have a fixed number of filters, typically from 3 to 12. Additionally, pixelized multispectral filters are not compatible with the use of compact-sized image sensors because the size of the pixelized filter limits the minimum pixel size.
Furthermore, the use of Fabry-Perot interferometers is known from previous publications U.S. Pat. No. 8,130,380 B and US 2015124263 A1.
The present invention aims to mitigate the problems of the previous solutions by providing a hyperspectral imaging arrangement that can be used to build a cost effective high performance hyperspectral imaging arrangement that is also compatible with small pixel image sensors enabling the construction of very low cost hyperspectral imaging arrangements based on mobile device cameras.